Topical drug delivery systems are known. These systems deliver drugs or other therapeutic agents, or other desired substances topically or transdermally, and may be designed to act locally at the point of application, or to act systemically once entering the body's blood circulation. In these systems, delivery may be achieved by techniques such as direct topical application of a substance or drug in the form of an ointment or the like, or by adhesion of a patch with a reservoir or the like that holds the drug (or other substance) and releases it to the skin in a time-controlled fashion.
Topical delivery systems for substances such as drugs, pain relieving compounds, vitamins, and skin improving compounds have been in use for a number of years. Transdermal delivery systems using creams have been developed for use with analgesics and skin refining compounds. However, these delivery systems do not work effectively for all compounds.
Peptides offer a promising approach for new therapeutics, but are generally considered to be poor drug candidates because of their low oral bioavailability and propensity to be rapidly metabolized. Thus, there exists a need for alternative routes of administration, e.g., topical or transdermal delivery.